Electrically controlled dashpot for carburetor throttles



June 3, 1952 R. R. STREBINGER 2,598,855

; ELECTRICALLY CONTROLLED DASHPOT FOR CARBURETOR THROTTLES Filed July 28, 1948 2 SI-IEETS-I-SHEET 1 INVENTOR. M RIC/MED ESTewmsnz BY 72/ z 24% .71 E ATTORNEY June 3, 1952 R. R. STREBINGER ELECTRICALLY CONTROLLED DASHPOT FOR CARBURETOR THROTTLES Filed "July 28, 1948 INVENTOR. PIC/MED fifirecamctz 2 SHEETS-SHEET 2 ATTOENE Y Patented June 3, 1952 ELECTRICALLY CONTROLLED DASHPOT FOR 'CARBURETOR THROTTLES Richard R. Strebinger, South Bend, Ind., assignor to Bendix Aviation Corporation, South Bend,

Ind., a corporation of Delaware Application July 28, 1948, Serial No. 41,115

The present invention relates to carburetors for internal combustion engines and more particularly to a throttle valve control mechanism for said carburetors.

In the operation of automobiles equipped with a fluid coupling or transmission, the engine sometimes stalls if the throttle valve is moved quickly to closed position when the vehicle is not in motion since under this condition rapid and almost complete deceleration of the engine is produced by the braking effect of the coupling or transmission. To prevent stalling of the engine, a mechanism such as a dashpot is often used to delay or retard momentarily the complete closing of the throttle valve so that a relatively gradual deceleration of the engine to normal idling speed is obtained. While the delaying effect of the dashpot permits satisfactory deceleration and prevents stalling of the engine, it is undesirable in the operation of an overdrive mechanism since the delaying eifect on the throttle valve tends to prolong the time required to synchronize the'en glue and vehicle. speeds for engagin the. overdrive. It is, therefore, one of the principal objects of the present invention to provide in a'carburetor for an internal combustion engine a mechanism for delaying the closing of the throttle valve only during the time whenthe vehicle is at a standstill or is traveling at a relatively slow rate of speed. v

Another object of the invention is to provide a relatively simple electrically controlled mechanismfor retarding the closing movement of the throttl valve under certain engine or vehicle operating conditions. 7

Additional objects and advantages will appear from the following description and accompanying drawings, wherein two arrangements of the invention are disclosed.

In the drawings:

Figure 1 is a side view of a carburetor incorporating my invention, in which the fuel bowl and throttle regulating mechanism are shown in cross-section;

Figure 2 is a top plan view of the main body of the carburetor shown in Figure 1;

Figure 3 is an enlarged cross-sectional view'of the throttle valve regulating mechanism taken on line 3-3 of Figure 1;

Figure 4 is a modification of the mechanism shown in Figure 3; and

Figure 5 is another sectional view of the mechanism shown in Figure 3 taken on line 5-5.

Referring more specifically to the drawings, numeral l5 designates an air horn of a single bar- 5 Claims. (Cl. 180-77) rel downdraft carburetor, numeral l2 2. fuel bowl mounted on and formed integrally with the main body, and M a throttle valve mounted on a shaft it in the throttle body l8, a flange 2U beingprovided at the base of said throttle body for securing the carburetor to an intake manifold (not shown). The throttle valve is adapted to be actuated by a throttle valve lever (not shown) mounted on one end of shaft I6. The fuel is delivered to the fuel bowl through conduit 24 and is controlled by a needle valve 26 and a float 28 mounted on a pivoted lever 30.

A dashpot, generally shown at 40, is provided to prevent rapid closing of the throttle valve when the vehicle is not in motion or is in motion but traveling at a relatively slow rate and consists of a cylinder v.42 disposed in thelower'portion of the fuel bowl and a reciprocable piston connected to the. throttle valve shaft I6 by a rod 46 journaled in a sleeve. 41 in the fuel bowl cover it, anda'rod 52 secured to theupper end cited 46 and to a lever 54 rotatably mounted onrthe end of the throttle valve shaft opposite the throttle valve lever. A'lever 56 for actuating the accelerating pump '(not shown) is rigidly secured to said shaft adjacent lever 54"and isiadapted to engage a lug 58 on onee'nd of lever 54 during the closing movement-of the throttle valve and rotate said lever in the direction to move piston 44 to the bottom of cylinder 42. A yieldable connection is also provided between the two levers by a spring 6% so that, in the opening movement of the throttle valve, lever 54 is moved in the direction to lift said piston. The spring permits the throttle valve to be moved farther after the upward limit of the piston stroke is reached. The position of stop screw 62, which is adapted to abut against a boss on the bottom side of the fuel bowl, determines the upward limit of the piston stroke.

The lower end of cylinder 42 is connected with the fuel bowl by a system of passageways 18 consisting of two parallel conduits l2 and 14 and two branch conduits 16 and I8 controlled by a ball valve adapted to seat over either orifice 82 or 84 of conduits l6 and 18, respectively, and thereby control the fiow of fuel to and from cylinder 42, orifices 82 and 84 being in themselves sufiiciently large to permit rapid intake anddischarge of fuel'through the two branch conduits. In the embodiment shown in Figure 3, conduit 78 is substantially unrestrictedand, when not closed by valve 86, permits rapid discharge of fuel from cylinder 42 so that the movement of piston 54 and the throttle is not retarded. Conduit 16, on the other hand, contains a calibrated restriction 85 which permits only a relatively slow flow of fuel through the conduit and, when conduit 18 is closed, the discharge of fuel from chamber 42 is sufficiently slow to substantially retard the closing movement of the throttle valve. When the delaying action of the dashpot is required, ball 80 is lifted and seated over an orifice 84 in conduit 18 by a magnetizable element in the form of a bar 88 projecting into branch conduit I8 immediately above orifice 84, said bar being mag netized by a solenoid coil the casing of which is indicated at 98, mounted on the side of the carburetor and controlled by some means responsive to vehicle speed. Bar 88 is sealed in the carburetor body to prevent fuel leakage by a snug fit between the bar and body defining the hole through which the bar extends and by a sealing and securing means 9|, shown in direct contact with the outside surface of the body. While the solenoid 90 is energized and bar ,88 thus magnetized, ball 88 is held over orifice 84, completely closing branch conduit 18, but leaving the restricted branch conduit 16 open for the slow discharge of fuel from cylinder 42. On the intake stroke of piston 44, the ball Bil readily becomes dislodged from either orifice 82 or 84 regardless of whether the solenoid is energized, and permits the rapid flow of fuel through both conduits '16 and [8 into cylinder 42 so that the dashpot has no retarding effect on the opening movement of the throttle valve.

In the operation of the present throttle valve regulating mechanism used in conjunction with a fluid coupling or transmission and an overdrive, the solenoid 9B is energized while the vehicle is at ,a standstill with. the motor running or in motion at a relatively slow speed so that ball valve 88 closes orifice 84, preventing the discharge of fuel through unrestricted branch conduit 18. As the piston'moves downwardly during the final stages of theclosing movement of the throttle valve,"fuel, which was drawn into the cylinder through both conduits l6 and 18 on the preceding opening movement of the throttle valve, is bled back into the fuel bowl through restricted branch conduit That a relatively slow rate, thus re-' tarding the downward movement of piston 44 and the closing movement of the throttle valve. On the intake stroke of piston 44, ball 80 is dislodged from orifice 84 in opposition to the magnetized bar and permits cylinder 42 to readily refill with fuel. As the speed of the vehicle approaches that at which the overdrive cuts in, the solenoid, which may be controlled by the governor for the overdrive, becomes de-energized and permits ball valve 80 to seat over orifice 82, thus opening orifice 84 so that the fuel may enter and discharge freely through conduit '18, thereby rendering the dashpot ineffective to retard the closing movement of the throttle valve. When the speed of the vehicle decreases to that at which the overdrive cuts out, bar 88 again becomes magnetized and reseats ball 80 over orifice 84 to prevent the discharge of fuel through the unrestricted conduit 18. Thus, the dashpot again becomes effective'to retard the final closing movement of the throttle valve; r

Another mechanism for performing the same functionis disclosed and claimed in copending application Serial No. 792,632, filed December 19, 1947, in the name of John F. Puro. 7

Other arrangements of elements than those shown in the accompanying drawings may be provided without departing from the scope of the present invention. For example, in the control 4 mechanism shown in Figure 4, the calibrated restriction 86 has been placed in branch conduit I8 and orifice 84 removed therefrom. With this arrangement, the dashpot is efiective to retard the movement of the throttle valve when the bar 88 is de-magnetized and is ineffective when the bar is magnetized and the ball is lifted by the bar from orifice 82 to the position shown by the dotted line. Further, a diaphragm forming a movable wall for a chamber such as. the lower end of cylinder 42 may be used in place of piston 44. Additional modifications of the present throttle valve regulating mechanism as well as other u'ses therefor will occur to those skilled in the art.

I claim: 1. In a carburetor for an internal combustion engine, an induction passage with a throttle valve therein, a fuel bowl, a chamber, a movable wall for said chamber, a linkage connecting said movable wall with the throttle valve actuating means for moving said wall in the direction to draw fuel into said chamber as the throttle valve is opened, and for moving said wall in the direction todischarge fuel from said chamber as the throttle valve is closed, a passageway connecting said chamber with the fuel bowl, a restriction in said passageway, a second passageway connecting said chamber with the fuel bowl. a valve for controlling said second passageway, an electrical coil controlled in response to a predetermined vehicle speed and having a stationary magnetizable core extending into said last mentioned passageway for closing said valve, and a means around said core for positively sealing said coil from said last mentioned passageway.

2. A dashpot for the throttle valve of a carburetor comprising a chamber, a movable wall, a passageway connecting said chamber with a source of fuel, a restriction in said passageway, a 7 second passageway connecting said chamber with V the source of fuel, an orifice in said second passageway, a valve element adapted to. close said orifice, a stationary member extending into said second passageway, an electrical means for magnetizing said member to cause said valve element to close said orifice, and a means for positively sealing said'electrical means from said last mentioned passageway.

3. A dashpot for the throttle. valve of a carburetor comprising a chamber, a movable wall, a passageway connecting said chamber with a source of fuel, a restriction in said passageway, a second passageway connecting said chamber with a source of fuel, an orifice in said second passageway, a valve element in said second passageway anterior to said orifice, a stationary bar extending into said second passageway through the wall thereof and being disposed posterior to said orifice, and an electrical means sealed from said second passageway for magnetizing said bar to cause said valve element to seat on said orifice.

4. A dashpot for the throttle valve of a carburetor having a fuel bowl comprising a cylinder, a piston, a passageway connecting said cylinder with the fuel bowl, a restriction in said passageway, a second passageway connecting said cylinder with the fuel bowl, an orifice in said second passageway, a valve element in said second passageway anterior to said orifice, a stationary bar extending into said second passageway through the wall thereof and being disposed posterior to said orifice, and an electrical means sealed from said second pasageway for magnetizing said bar at predetermined vehicle speeds to cause said valve element to close said orifice.

5 5. A dashpot for the throttle valve of a carburetor having a fuel bowl comprising a cylinder, a piston, a passageway connecting said cylinder with the fuel bowl, a restriction in said passageway, a second passageway connecting said cylinder with the; fuel bowl, an orifice in said second passageway, a ball for closing said orifice disposed in said sec nd passageway anterior to'said orifice, a station ry bar extending into said second passageway through the wall thereof and be- I ing disposed posterior to said orifice, and an electrical means sealed from said second passageway for magnetizing said bar at predetermined en- The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,960,432 Barker et a1. May 29, 1934 2,144,153 'Henning Jan. 17, 1939 2,296,646 Matulaitis Sept. 22, 1942 

